Number 261 - February 2005
	How Old Newsletters Can Save Your Skin
by Bob Thomson, TOGGLE Editor, Tacoma Open Group for Microcomputers
Do you save your old newsletters? I do and, on several occasions, have thanked the Lord that I do.    Recently my computer hard disk crashed and I lost access to my files. When the computer was restored to health it had a new motherboatd and a new hard disk, disk C:. I kept the old hard disk as disk D:.The operating system on disk D: was defunct but the files on it were still intact--sort of.    Those of you who know me well, know that I am of Scottish descent. I don't spend money on something unless I can see real value in it. I use those things that I have as long as they are working--not seeing the need to upgrade just for the sake of upgrading. Okay! Okay! I'm a cheapskate!    I still often "drop down" into DOS to run programs that predated Windows. Two MSDOS programs that I still run regularly are the word processor, WordStar and the old (now defunct?) spreadsheet, SuperCalc.    WhenI tried to access my SuperCalc files they came up but when I tried to maneuver within them the cursor jumped to the "Home" cell. No matter what I did, I couldn't get SuperCalc to work properly. I was really puzzled. After trying to maneuver in several files I noticed that some files seemed to load and work OK while others others did not. Then it dawned on me. The files that bombed contained the SuperCalc date function, TODAY. When TODAY is entered into a cell, the program is supposed to capture today's date from the computer-stored date and use it in date-related entries/formulas.    I remembered that SuperCalc, which was first issued in about 1980, had a programmed-in "drop-dead date" of the end of the year 1999. That meant that the TODAY function would not work beyond December 31st of that year. The TODAY function was based on a number called the Julian Date. The Julian date is the number of days since the Calendar date was adjusted in the 1500's to add a leap day every four years to adjust for the sidereal	shift since Roman times that had put the calendar out of sync with the seasons. The number used in SuperCalc wasn't a true Julian date--it was the number of days since March 1st, 1900. However, it served the same purpose.    I also remembered that I had found a remedy for that problem and, after applying the correction to my copy of SuperCalc, had reported it in an earlier TOGGLE newsletter. Somehow or other that date correction had been clobbered in the disk failure that required the rebuild of my computer. After a search of old TOGGLEs, the correction to the TODAY function was found in the November 2000 issue in an article titled "Modifying TODAY in SuperCalc 4". I pulled out that issue, which I had saved, and made the appropriate correction to the SuperCalc program to extend the valid period to something like 2100 AD. Now all my spreadsheets using the TODAY function work fine again.    How did I modify the program? Oh yeah. I used the old DOS program DEBUG. You old timers remember that don't you? From the DOS prompt your enter DEBUG and it responds with a hyphen prompt, after which you enter DEBUG commands. You get out of DEBUG with the QUIT command. It is a bit dangerous to use because you are modifying the basic code of the program, but you NEVER work on the only copy (original) of a program. You ALWAYS work on a copy of the program to make sure that the modification works before you proceed to use it. Note:    On my updated computer DEBUG works in the DOS window which opens within Windows XP but does NOT work in the full screen version of DOS which I can open on Start-up as an alternative to Windows XP. If you are unfamiliar with or have forgotten this command and wish to see how this works dig out your copy of the November 2000 TOGGLE, or call up the November 2000 newsletter and read it online at our website www.toggle.org.
Number 262 - February 2005